Hide Glue and the Electric Glue Pot

Approximately two years ago, I purchased an electric glue pot with a 1 pound bag of 192 gram hide glue flakes from Tools for Working Wood. My mission is to be able to use the hide glue for all forms of joinery and veneering like it was done in the 18th century. The problem is that the glue pot didn't come with any instructions. Since then the pot and glue have been sitting around waiting for discovery.

What are your recommendations on how to use the glue pot? What does anyone know about gram strength? Is my initial bag of hide flakes still usable after all this time? What is the technique for applying the glue to the wood surface? I have added some photographs of the pot and glue to give everyone a visual aid.

You're pot is identical to (post #148196, reply #1 of 15)

You're pot is identical to mine, excepting I also have a round lid to reduce evaporation when the pot is on.

Many sources recommend 192 for general furniture work, as opposed to some of the other common strengths. Since I don't use glue every day, I mix in empty clean soup and vegetable cans, 2 parts by weight cold water to 1 part ground hide glue. Let sit at least 30 mninutes. Put the can in the copper liner, and the bent wire piece will hold the can down. Add water to the copper liner at least as high as the water-glue mix, and plug in. When the water-glue mix is melted it's ready to use. Most people simply mix the water and glue in the copper liner.

For dovetails, mortises, and tenons, I apply the glue with an "acid brush"; for gluing boards edge to edge I use an inexpensive 1" paint brush. If the paint brush holds too much glue, cut off the last 1/2" of bristles. The glue doesn't gell as quickly if the thermostat in the workshop has been set to 75 deg F for at least 12 hours. In a pinch, you can warm surfaces to be glued with a few minutes of a hot air gun.

After the glue has been spread and the pieces clamped, don't forget to unplug the glue pot. The cooled glue can be left on the worktable. After a few days at room temp, the surface of the cold glue may grow some mold and such; the next time the glue is heated, most people simply capture the mold with a tongue depressor or similar and throw away. For longer storage, some keep the cold glue in a fridge to slow down mold growth.

If the pot is left on for more than a few minutes, moisture will evaporate from the surface of the hot glue, producing a dry film on the surface. I used to mix back in, but that just makes the glue thicker; now I scrape off and throw away. Over repeated heatings and/or extended heating, the entire can or pot of glue will thicken as water evaporates - simply add some more water to thin. I've tried many times to memorize the look of fresh 2:1 glue but still can't judge how much water to add.

As a general rule, I'll gently remove the clamps after about 4 hours, but not stress the glued joint for 24 hours.

Hide glue does have some internal cohesion, allowing creation of rub joints - apply glue to both surfaces, bring them together and slide back and forth under moderate hand pressure a couple times, then set aside for 24 hours without clamps.

Don, I have a question on (post #148196, reply #2 of 15)

Don, I have a question on hide glue also, when you say two parts water by weight to the glue, is it an even mix, meaning 16oz water to 16oz of glue flakes?. I bought some inexpensive veneer to play with and would like to try what Joe mentioned, thank you for any help on this. garyowen

Never tell a man how to do something,Tell him what to do and let him surprise you with his ingenuity. Gen.George S.Patton

Joe,
To simplify things for (post #148196, reply #3 of 15)

To simplify things for you,the soup can in a water bath is a good idea if you don't want to have to clean the liner periodically. Personally I just mix glue in the liner.

You don't need to weigh out the glue and water. Just put a quarter cup or so of glue in your container and cover with cold tap water.Let stamd for an hour or so to swell the glue and pour off any excess water. Heat the glue and see how it runs off the brush. It should be a steady stream the consistancy of hot maple strup. If it's too thick add a little warm water, stir and let come back to temp. If it's too thin, let it cook a while.

To test glue for usability, put some on your thumb and rub between thumb and forefinger til most of the glue is squeezed out, then pull the fingers apart multiple times and you should get threadlike filaments between the surfaces of tour fingers/

The higher the gram strength, the quicker it gels. 192gs is the most common and good for all wood applications.

All,
While it doesn't hurt (post #148196, reply #4 of 15)

While it doesn't hurt anything to let the glue soak in the water before heating, neither is it necessary. You can just put the glue into the water and warm it up if you are in a hurry. As soon as the glue melts, stir it up and it is good to go. Neither is the proportion of water to glue critical- it's not like epoxy. The common "test" for "strong enough" is to pull the brush out of the pot,, and let the glue run off. If it runs in a stream, it's good, if the stream breaks into beads or drops, it's too thin for most work. If it hangs in a glob, it's too thick;-) (That said, thinned glue is handy for temporary joins, like stacking veneers with paper between for sawing figural inlays. It is strong enough to hold things together, but can easily be separated later. In addition, I have used thinned glue in repairing failed crossgrain construction in period antiques, where you would want the joint to fail again, rather than causing the wood to split.)

Glue that's too thin will not skin over in the pot, so if your glue is not getting a skin, just add some more glue and stir it up after a few minutes. If you are using the glue on a daily basis, it will cook down and thicken; add some water from time to time, as you use it up, add some glue and water to keep the level up in the pot. As you use the stuff you'll get used to the way it looks and handles.

Hi to, rwdare, and (post #148196, reply #5 of 15)

Hi to, rwdare, and joinerswork. Thanks to both of you for the help with the glue question. This is a small piece of what I want to learn, in the many different areas of woodworking. I have been wandering about in here, giving advise if I am comfortable with the subject, and picking up many helpful hints and tips. Again Thanks to both of you for your help. garyowen

Never tell a man how to do something,Tell him what to do and let him surprise you with his ingenuity. Gen.George S.Patton

Dan,
You had a photo of a (post #148196, reply #9 of 15)

You had a photo of a candle box here on Knots. Could you tell me where I might learn more abou the design of the box. I believe the original is in a museum in NC. I don't need much. The height, weight, length amd thickness of the wood. . a phrase about the moulding around the bottom. I believe the box is dovetailed but is mitred at the top. I believe the top is a raised panel and it slides in grooves along the two long sides. I would guess the bottom sits in four grooves.

Mel, and Dan,
I have made (post #148196, reply #11 of 15)

I have made these boxes for Old Salem to sell in their gift shop for about 30 yrs.

Old Salem used to sell a blueprint for this box, drawn by Carlyle Lynch, for folks to make them for private use. They (as most museums do) take a dim view of people making reproductions of their stuff for sale, unless they get a royalty.

Back around 1980, Carlyle drew the box, and several other items in the old Salem collection. The idea was that they would sell the blueprints- he had 3 or 4 of them altogether, as I recall- in the gift shop. He asked me to build a box to "prove" his drawing. On a lark I took my prototype box to Old Salem, to compare it to the original while visiting friends nearby, and ended up with an order for a half dozen of them. The rest, as they say, is history.

Dan, are you going by Carlyle's blueprint, or from seeing the original in the single brothers' hall? Cutting the dovetails with the miter on the stuck mold is a nice job, isn't it? Did you notice, however, that the original has a "mason's miter", that is, at the corner, the molding is carved into a miter on the dovetail, not truly mitered?

Contrary to Dan's construction with a veneered panel w/applied molding for the bottom, the original is a molded edge thin board, frankly nailed onto the bottom of the box, with pretty large roseheaded nails. I do the same, except I use smaller square cut "sprigs", and countersink them, so the nail's heads can't scratch a table top's finish.

Dan,
Thanks for the link (post #148196, reply #13 of 15)

Thanks for the link and the info on the box. Didn't mean to take you away from your work. I love the desk you are making. I neve see walnut that figured in the Woodcraft that I work at. :-) i will try to find the stuff you posted about the box in the old FWW website.

walnut crotch source (post #148196, reply #14 of 15)

If you want to get in the high figured stuff this is a good start. Most of the guys I deal with are up in Virginia actually. They don't like computers, internet or slick deals. I go up on their phone call letting me know its time. Only cash and discounts if you take the whole thing type stuff.

On the other hand, this guy over in Tenn. is a different cat. By the way, don't be fooled by the down home address. On the other end is Alf. Yea Alf. Oh thought I might mention: he's one of the guys on the list of Cartouche Recipients from SAPFM. This guy is the real deal.

He loves to work with you. Take a look at the site and get some ideas on the wood you like. He'll send photos and deal straight business. My only hesitation is you'll be getting into my stuff. Ha.

Alf said he welcomes buyers. His prices are very good and his stock is top notch.

If you get in this zone be prepared to power up your bandsaw and get a GOOOOOOOOOOOOOOOOOD resaw blade. Lenox and Laguna come to mind... not woodslicer stuff. Its an investment of sorts but the quality jump is big.

I know there are lots of guys that think 10/bf is too much. After 250 hours on a project its pennies. I have never finished a big project and said "boy I wish I got the cheap stuff" this is too nice.

Dan,
Alf is a real (post #148196, reply #15 of 15)

Alf is a real resource. That wood is gorgeous. Your buyer is getting something unique, and beautiful. I don't get to Tennesee much. (once in 66 years), but I spend a lot of time in Virginia. Are you willing to divulge a good source or two in VA?

On bandsaw blades. I just got a new Powermatic 14" bandsaw, and I do need to get a good blade for resawing. You mentioned Lenox and Laguna. Since you have the experience and I don't, which would you recommend. Please give me enough info on the name of the blade so that I can order the right one.

I fully agree with you on GREAT wood. People don't care which tools you used to make your piece or whether it was made with hand or power tools, BUT THEY LOVE BEAUTIFUL WOOD.